In the field of industrial manufacturing and automatic control, a server motor and a ball screw are used to drive and control the position of straight-line motions in conventional. Since the growing and competition of main application fields, such as semiconductor industry, electronic industry, photoelectric industry, medical apparatus and automatic control, are fast and intense, the requirements of the linear motion performances of the motors arise day by day. The motors are required to have high speed, low noise and high positioning accuracy. Under this circumstance, the conventional server motors and the mechanical motions are replaced by the linear motors in many applications.
In general, although the conventional linear motors of the motor set can be independently operated, it is still hard to minimize the mechanism size, increase the driving force and make the magnetic fields independent with each other in the same time. On the other hand, the conventional linear motors has to be integrated with a sliding guide and a sensing unit, and an extra requirement of spaces will exist when the integration is not perfect or when other demands has to be met.
Please refer to FIG. 1A. FIG. 1A schematically illustrates the structure of a conventional linear motor. As shown in FIG. 1A, the conventional linear motor 1 includes a case 10 and an axial portion 11, the winding used by the conventional linear motor 1 is wound around the axial portion 11 and disposed inside the case 10. Because the winding is circle-shaped or ring-shaped, the total length of the conventional linear motor 1 has to be increased when the driving force of the motor is required to be enhanced due to the limitations of the height or the width of the conventional linear motor 1. However, when the ratio of length to width of the conventional linear motor 1 becomes too much larger, the mechanical rigidity becomes worse and the machining becomes more difficult, and even processing issues will occur during winding and adhesion.
Please refer to FIG. 1B. FIG. 1B schematically illustrates the structure of a motor set using the conventional linear motor. As shown in FIG. 1B, a plurality of the conventional linear motor 1 are applied to a motor set 100. Except for the drawbacks mentioned above, a disturbing issue usually happens because of the open magnetic fields of the conventional linear motors 1 of the motor set 100. In other words, the magnetic fields of the conventional linear motors 1 disturb each other. Meanwhile, the cases 10 of the conventional motors 1 are closely connected, so that the surface temperature of the covers 10 will be too high to disable the sensing unit connected with the motor set 100.
There is a need of providing a linear motor and a motor set using the same to obviate the drawbacks encountered from the prior art.